Magnetic tooth alignment devices and related methods

ABSTRACT

A magnetic tooth alignment device includes a first magnetizable element configured to be adhered to a tooth. The magnetizable element may be a magnet, a metal, or another magnetizable material. An aligner tray is configured to partially encase a plurality of teeth and the first magnetizable element. A secondary magnet holder is configured to partially encase the aligner tray. The secondary magnet holder includes a secondary magnet configured to magnetically interact with the first magnetizable element when the secondary magnet holder is partially encasing the aligner tray. An inner wall of the aligner tray includes a cavity and the inner wall is configured to stop movement of the tooth when the first magnetizable element enters the cavity and contacts the inner wall of the aligner tray. The aligner tray in implementations couples with the plurality of teeth using only a friction fit.

CROSS REFERENCE TO RELATED APPLICATIONS

This document claims the benefit of the filing date of U.S. ProvisionalPatent Application No. 62/025,959, entitled “Magnetic Tooth AlignmentDevices and Related Methods,” naming as first inventor ChristianHoybjerg, which was filed on Jul. 17, 2014, the disclosure of which ishereby incorporated entirely herein by reference.

BACKGROUND

1. Technical Field

Aspects of this document relate generally to orthodontic devices.Specific implementations relate to orthodontic alignment devices.

2. Background Art

Orthodontics is a branch of dentistry dealing with alignment of theteeth and/or jaws of a patient. Conventional devices used for toothand/or jaw alignment include traditional metal dental braces adhered tothe teeth or rigid plastic trays that are not permanently affixed to theteeth. After the desired alignment has been achieved using conventionaldevices, retainers are often used to prevent the teeth/jaw fromreturning to pre-alignment positions.

SUMMARY

Implementations of magnetic tooth alignment devices may include: a firstmagnetizable element configured to be adhered to a tooth of a patient;an aligner tray configured to at least partially encase a plurality ofteeth of the patient and the first magnetizable element, and; asecondary magnet holder configured to at least partially encase thealigner tray, the secondary magnet holder including a secondary magnetconfigured to magnetically interact with the first magnetizable elementwhen the secondary magnet holder is partially encasing the aligner tray.

Implementations of magnetic tooth alignment devices may include one,all, or any of the following:

The aligner tray may be formed of a polymer.

The aligner tray may be transparent.

The aligner tray may include no magnets.

The aligner tray may be configured to couple with the plurality of teethof the patient using only a friction fit.

The aligner tray may be configured to fully encase the plurality ofteeth of the patient and to fully encase the first magnetizable element.

The aligner tray may include a protrusion defining a cavity between thealigner tray and the first magnetizable element.

The secondary magnet holder may be shaped substantially similar to thealigner tray.

The secondary magnet holder may be configured to couple with the alignertray using only a friction fit.

The first magnetizable element may be formed of one of a powderedmagnetic material mixed with an adhesive and a cement magnetic material.

An inner wall of the aligner tray may be configured to stop movement ofthe tooth when the first magnetizable element contacts the inner wall ofthe aligner tray.

Implementations of magnetic tooth alignment devices may include: a firstmagnetizable element configured to be adhered to a tooth of a patient;an aligner tray configured to at least partially encase a plurality ofteeth of the patient, the aligner tray including a protrusion defining acavity between the aligner tray and the first magnetizable element, thealigner tray including no magnets; and; a secondary magnet holderconfigured to at least partially encase the aligner tray, the secondarymagnet holder including a secondary magnet configured to magneticallyinteract with the first magnetizable element when the secondary magnetholder is partially encasing the aligner tray.

Implementations of magnetic tooth alignment devices may include one,all, or any of the following:

The secondary magnet holder may be configured to couple with the alignertray using only a friction fit.

The aligner tray may be formed of a polymer.

The aligner tray may be transparent.

The secondary magnet holder may have a shape substantially similar tothe aligner tray.

The secondary magnet may have a dental arch shape.

Implementations of magnetic tooth alignment devices may include: a firstmagnet configured to be adhered to a tooth of a patient; an aligner trayconfigured to at least partially encase a plurality of teeth of thepatient and the first magnet, and; a secondary magnet holder configuredto at least partially encase the aligner tray, the secondary magnetholder including a secondary magnet configured to magnetically interactwith the first magnet when the secondary magnet holder is partiallyencasing the aligner tray.

Implementations of magnetic tooth alignment devices may include one,all, or any of the following:

The aligner tray may include no magnets.

The secondary magnet holder may have a shape substantially similar tothe aligner tray.

The foregoing and other aspects, features, and advantages will beapparent to those artisans of ordinary skill in the art from theDESCRIPTION and DRAWINGS, and from the CLAIMS.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will hereinafter be described in conjunction with theappended drawings, where like designations denote like elements, and:

FIG. 1 is a front view of an implementation of a magnetic toothalignment device;

FIG. 2 is a side view of the magnetic tooth alignment device of FIG. 1;

FIG. 3 is a side cross-section view of an implementation of a magnetictooth alignment device;

FIG. 4 is a top see-through view of an implementation of a secondarymagnet holder of a magnetic tooth alignment device;

FIG. 5 is a side see-through view of the secondary magnet holder of FIG.4;

FIG. 6 is a side cross-section view of an implementation of a magnetictooth alignment device;

FIG. 7 is a side cross-section view of an implementation of a magnetictooth alignment device;

FIG. 8 is a front exploded view of an implementation of a magnetic toothalignment device for an upper row of teeth;

FIG. 9 is a front exploded view of an implementation of a magnetic toothalignment device for a bottom row of teeth;

FIG. 10 is a side cross-section view representatively illustratingextrusion of a tooth using an implementation of a magnetic toothalignment device;

FIG. 11 is a side cross-section view representatively illustratingintrusion of a tooth using an implementation of a magnetic toothalignment device;

FIG. 12 is a side cross-section view representatively illustratingrotation of a tooth using an implementation of a magnetic toothalignment device;

FIG. 13 is a side cross-section view representatively illustratingbodily movement (proclining or reclining) of a tooth using animplementation of a magnetic tooth alignment device;

FIG. 14 is a top view representatively illustrating expansion of teethor a jaw using an implementation of a magnetic tooth alignment device;

FIG. 15 is a top view of an implementation of a first primary magnet ofa magnetic tooth alignment device;

FIG. 16 is a side view of the first primary magnet of FIG. 15;

FIG. 17 is a perspective view of the first primary magnet of FIG. 15;

FIG. 18 is a top view of an implementation of a second primary magnet ofa magnetic tooth alignment device;

FIG. 19 is a side view of the second primary magnet of FIG. 18;

FIG. 20 is a perspective view of the second primary magnet of FIG. 18;

FIG. 21 is a top view of an implementation of a third primary magnet ofa magnetic tooth alignment device;

FIG. 22 is a side view of the third primary magnet of FIG. 21;

FIG. 23 is a perspective view of the third primary magnet of FIG. 21;

FIG. 24 is a top view of an implementation of a secondary magnet of amagnetic tooth alignment device;

FIG. 25 is a side view of the secondary magnet of FIG. 24;

FIG. 26 is a perspective view of the secondary magnet of FIG. 24;

FIG. 27 is a top view of an implementation of a secondary magnet of amagnetic tooth alignment device;

FIG. 28 is a side view of the secondary magnet of FIG. 27, and;

FIG. 29 is a perspective view of the secondary magnet of FIG. 27.

DESCRIPTION

This disclosure, its aspects and implementations, are not limited to thespecific components, assembly procedures or method elements disclosedherein. Many additional components, assembly procedures and/or methodelements known in the art consistent with the intended magnetic toothalignment devices and related methods will become apparent for use withparticular implementations from this disclosure. Accordingly, forexample, although particular implementations are disclosed, suchimplementations and implementing components may comprise any shape,size, style, type, model, version, measurement, concentration, material,quantity, method element, step, and/or the like as is known in the artfor such magnetic tooth alignment devices and related methods, andimplementing components and methods, consistent with the intendedoperation and methods.

Referring now to FIG. 1, a front see-through view of an implementationof a magnetic tooth alignment device (device) 4 is shown coupled to anupper row of teeth 2. FIG. 2 shows a side see-through view of the device4 coupled to an upper row of teeth, with the roots of the teeth visible.FIG. 3 is a side cross-section view of the device 4 coupled to an upperrow of teeth. FIG. 4 is a top view of an implementation of a secondarymagnet holder 14 of device 4, showing the top 20 of the secondary magnetholder. FIG. 5 is a side view of the secondary magnet holder 14.

Referring now to FIG. 1, in various implementations, a magnetic toothalignment device 4 includes a magnetizable element 5 coupled to a tooth2. The magnetizable element 5 is an element which may be attracted by amagnet. As such, the magnetizable element could be formed of a solidmetal, or metal powder mixed in a binder, and so forth. In otherimplementations the magnetizable element could be, itself, a magnet,such as primary magnet 6 shown in FIG. 1. In implementations in whichthe magnetizable element is a magnet it is capable of being not onlyattracted by another magnet but also repelled by another magnetdepending on how the poles of the magnets are oriented relative to eachother.

An aligner tray 12 is couples to/over/partially over one or more teethand is provides a stopping point for movement of the one or more teeth,and a secondary magnet holder 14 couples to the aligner tray. Thesecondary magnet holder has one or more secondary magnets 22 therein(and/or thereon).

The primary magnets 6 may be tooth-colored or may have some other colorthat allows them to blend in well with the color of the teeth. Forinstance the outer color of the primary magnets 6 may be, in variousimplementations, selected from at least the shades A1, A2, A3, clear ortransparent. The primary magnets 6 may include a magnetic portion and asurface covering the magnetic portion. In such implementations, thesurface covering may be a composite material and/or may be tooth coloredto help the primary magnets 6 visibly blend in with the appearance ofthe teeth.

In FIG. 1 the primary magnets are shown on the front (buccal side) ofthe teeth, while FIG. 3 illustrates how the primary magnets 6 may alsobe placed on the back (lingual) side of the teeth. The primary magnets 6may be placed on the teeth with a glue, cement, or other materialcapable of bonding/coupling the magnet to the tooth 2. Depending uponthe material used, the primary magnets 6 may later be removed byapplying a solvent to the glue, cement, or other bonding/couplingmaterial. Although the primary magnets 6 are only shown on the front(buccal) and back (lingual) faces of the teeth, they may also be placedor attached to any other exposed surface of a tooth 2. A magnetic toothalignment device may include any number of primary magnets on any numberof teeth. For instance, in some cases there may be only one tooth thatneeds movement and, in that case, there may be only one primary magnet,or there may be multiple magnets at different locations on that onetooth, to assist in movement of that tooth over time in a desireddirection(s) during orthodontic treatment. For example, in FIG. 3 thereis shown a first primary magnet 8 on the front (buccal) side of thetooth 2 and a second primary magnet 10 shown on the back (lingual) sideof the tooth 2. In other cases there may be multiple teeth that needmovement. Accordingly, in various implementations there may be aplurality of teeth to which a plurality of primary magnets are attached.

In various device implementations, any type of magnetic material may beused for the primary magnets, though in some implementations rare-earthelement magnets may be used in order to develop sufficient magneticforces while using appropriately-sized magnets. By non-limiting example,the primary magnets in implementations may include neodymium. In otherimplementations the primary magnets may be formed of other magneticmaterials, including magnetic alloys, ferromagnetic alloys, and thelike.

The primary magnets may take many cross sectional and three dimensionalshapes. Some shapes may be anatomically designed to match specificteeth. In some implementations of magnetic tooth alignment devices theprimary magnets may all have the same, or substantially the same shape,which may be an average shape designed to work with the majority oftooth structures.

Referring to FIGS. 1-5, the magnetic tooth alignment device alsoincludes an aligner tray 12. After the magnetizable elements, such asprimary magnets, are glued, cemented, bonded, coupled, or otherwiseadhered to the teeth, the aligner tray 12 is coupled over the teeth or,in other words, may partially encase/enclose, or fully encase/enclose,the teeth. In the figures the aligner tray 12 fully encases the teeth,but the practitioner of ordinary skill in the art may envision versionsin which the teeth are not fully encased. The aligner tray 12 may beformed of a clear polymer, though it may also be formed of anon-polymeric material, a composite material, and/or an opaque material.The aligner tray 12 is selectively attached to the teeth with a frictionfit and, accordingly, may be slid off or on the teeth as desired by auser by overcoming the friction between the tray and the teeth. Thealigner tray 12 will cover or surround, at least partially (and in someimplementations completely or substantially completely) at least onetooth that is to be moved (and in many cases several or many teeth thatare to be moved). The structure of the aligner tray 12 provides thestopping point for tooth movement during magnetic orthodontic alignmentand accordingly each single-tooth portion of the aligner tray 12 isconfigured so that when the tooth abuts/contacts it (or when themagnetizable element attached to the tooth abuts/contacts it) the toothwill be in the desired position for that stage of orthodontic treatment.Thus the aligner tray 12 is sufficiently rigid, and the magnetic forcesof the primary and secondary magnets of such a magnitude, that when theteeth reach the aligner tray 12 they do not, or substantially do not,distort or move the tray—but instead stop further movement uponcontacting the surface of the tray.

For example, a primary magnet may be attached to the buccal side of atooth and an attractive opposite poled secondary magnet may be used todraw that tooth in the buccal direction, or in other words towards theinner buccal sidewall of the aligner tray. As another example, a primarymagnet could be attached to the buccal side of a tooth and aligned sothat similar poles of the primary magnet and secondary magnet are nearone another to provide a repulsive force so that the tooth is pushedback towards the lingual side of the aligner tray. Thus, the primary andsecondary magnets may utilize magnetic attraction and/or repulsionthrough opposite and same magnetic poles in order to achieve the desiredmagnetic force and direction though, as described above, when onlyattraction is needed the magnetizable element need not be a magnet.Additionally, any type of orthodontic tooth movement may be accomplishedusing implementations of a magnetic tooth alignment device including,but not limited to, extrusion, bodily movement, intrusion, expansion,and the like.

During the process of orthodontic treatment using magnetic toothalignment devices, several differently shaped aligner trays may be usedat different stages so as to ensure incremental movement of the teeth ata desired rate. Thus when one or more teeth have reached a location ofabutting a particular/first aligner tray, that first aligner tray may beswitched out with another/second aligner tray to provide new boundariesfor the teeth to reach as they move under the magnetic forces.

Referring still to FIGS. 1-5, the magnetic tooth alignment deviceincludes a secondary magnet holder 14 including one or more secondarymagnets 22. The secondary magnets 22 may be placed in differentlocations within or on the secondary magnet holder 14. In theimplementations shown in FIGS. 1-5 there are four secondary magnets 22and they are each encased within a bottom section of the secondarymagnet holder 14, and the magnets are generally shaped and positioned toalign with a dental arch. In other implementations, the secondary magnet22 may be a single magnet shaped and positioned to align with a specificlocation along the dental arch. Referring to FIG. 3, the secondarymagnet holder 14 could, alternatively or additionally to having thesecondary magnet(s) housed in the bottom 16 of the secondary magnetholder, have one or more secondary magnets in or on the front 18 of thesecondary magnet holder.

The secondary magnet holder 14 is configured to selectively couple atleast partially, and in some cases fully or substantially fully, overthe aligner tray 12. In various implementations, this coupling isaccomplished with a friction fit between the secondary magnet holder 14and the aligner tray 12, this friction fit being able to be overcomemanually by a user. In other implementations the secondary magnet holder14 is configured to selectively couple over the aligner tray 12 througha clip-on mechanism which also may be overcome through the manual forceof a user to remove the secondary magnet holder. In otherimplementations, the coupling may take place at least in part throughthe magnetic forces between the primary and secondary magnets.

Referring to FIG. 3, a number of tooth movement operations may beaccomplished by altering sizes, magnetic strengths, locations andpolarities of the primary and secondary magnets of a magnetic toothalignment device. By non-limiting example, in the implementation shownin FIG. 3, the first primary magnet 8 could be attracted to thesecondary magnet 22 and the second primary magnet 10 could also beattracted to the secondary magnet 22 and this could result in pullingthe entire tooth downwards towards the secondary magnet 22 (resulting inextrusion of the tooth 2). However, the first primary magnet 8 could beattracted to the secondary magnet 22 and the second primary magnet 10could be repelled by the secondary magnet 22 and this could result in arotation of the longest length of the tooth so that the bottom of thetooth is moved farther away from the front of the aligner tray(resulting in tipping of the tooth 2). The opposite rotation could beaccomplished by reversing the polarities of the first and second primarymagnets 8, 10 (or only that of the secondary magnet 22). Both the firstand second primary magnets 8, 10 could have a polarity such that theyare repelled by the secondary magnet 22 and this could tend to push thetooth upwards away from the secondary magnet (resulting in intrusion ofthe tooth 2) or to otherwise prevent or hinder downward movement of thetooth during the orthodontic treatment. The size and the strength of themagnets may be altered, as well, to increase or decrease the rate atwhich movement occurs, or to alter the forces on the teeth to achievethe desired movement, and so forth. As there may be many possiblevariations on the size, strength, polarity, and position of the variousmagnets of a magnetic tooth alignment device, these variables may bechosen so as to accomplish the desired tooth movement.

During orthodontic treatment when the secondary magnet holder 14 iscoupled to the aligner tray 12, the secondary magnet(s) 22 generallystay fixed while each primary magnet 6 moves either towards or away froma secondary magnet 22 to effectuate movement of the teeth to which theprimary magnets are attached. Once the full desired movement of theteeth has been accomplished, the patient discontinues using thesecondary magnet holder and the aligner tray. The primary magnets areremoved from the teeth, and a retainer is fabricated and/or used toretain the teeth in their final, proper aligned positions. Inimplementations the retainer may be clear and/or may otherwise besimilar in some respects to the aligner tray, and in implementations maybe, by non-limiting example, a vacuum-formed retainer formed using apolymer sold under the trade name ESSIX by Dentsply International Inc.of York, Pa., a thermo-formed retainer formed using a polymer sold underthe trade name ZENDURA by Bay Materials, LLC of Menlo Park, Calif., afixed retainer, a Hawley retainer, or the like. In variousimplementations, the aligner tray 12 may also be formed of the ESSIX orZENDURA materials.

The secondary magnet holder 14 may be re-utilized in cases where theteeth begin to relapse. In the case of relapse one or more primarymagnets 6 may be coupled to the tooth 2 or teeth again and windows maybe cut in the retainer (if the retainer would otherwise interfere withthe primary magnet(s) to allow the magnet(s) to pass therethrough, or aretainer with protrusions/cavities to receive the magnets could be used(similar to aligner tray 34 discussed below), and the secondary magnetholder 14 may be utilized again. In such an instance the retainer itselfacts as an aligner tray.

In some implementations, the secondary magnets 22 will be completely orsubstantially encased within the secondary magnet holder. In otherimplementations they may be attached to the outside of the secondarymagnet holder or only partially encased therein. The secondary magnetholder may be formed of a polymer material, which may be any of thosedisclosed in this document, though in other implementations it could beformed of some other material, such as a composite material. In someversions the secondary magnets may be removable from the secondarymagnet holder.

In implementations the aligner tray 12 itself could include magnets, orthe secondary magnets could be attached directly to the aligner tray. Insome versions of a magnetic tooth alignment device a chewable elementmay be used. By non-limiting example, in some implementations thesecondary magnet holder may not attach to the aligner tray but maycomprise a chewable element that includes a secondary magnet therein,and the magnetic forces between the primary magnets and secondarymagnet(s) operate while the patient is chewing on the secondary magnetholder. The secondary magnet holder in such implementations may beformed of a rubbery polymer or a rubbery composite material. Thesecondary magnet holder in such instances could be an aligner trayseater sold under the trade name CHEWIES by Dentsply Raintree Essix ofSarasota, Fla., with a secondary magnet placed therein (and/or retainedtherein such as with a glue or cement). In implementations the secondarymagnet holder may have a shape somewhat different than CHEWIES alignertray seaters such as, by non-limiting example, a shape of a block, cubeor right rectangular cuboid having a cavity therein receiving thesecondary magnet.

A number of orthodontic treatment method implementations may be employedwith the implementations of magnetic tooth alignment devices disclosedin this document. In a first method, the primary magnets, secondarymagnet(s) and secondary magnet holder are provided. A dentalpractitioner (such as an orthodontist or an assistant) attaches theprimary magnets to the teeth and then takes an impression of the teethwith primary magnets coupled thereon. The impression is used to form analigner tray with proper dimensions to begin magnetic orthodontictreatment. This method may result in fewer refinements needing to bemade to aligner trays, since the trays are custom built for the patient,which may result in less treatment time for the dental practitioner andpatient, lower cost for the patient and/or a lower cost or higher profitfor the dental practitioner. It may also result in a lower cost ordecreased time for the party that provides the alignment tray sincethere may be fewer revisions to each tray.

In a second method of orthodontic treatment, a dental practitionerattaches the primary magnets to the teeth and then takes an impression(such as, by non-limiting example, a polyvinyl siloxane (PVS)impression). This impression is used to pour a model with dental modelstone. The teeth of the dental model stone are manually placed in theirdesired locations and then used in the aligner tray manufacturingprocess to create an aligner tray. The resulting aligner tray is worn bythe patient, along with the secondary magnet holder which has one ormore secondary magnets, until the desired movements of the teeth areaccomplished (which may involve the use of other incrementally changingaligner trays as discussed herein). Once the teeth have reached theirdesired positions, the primary magnets may be removed from the teeth anda retainer may be formed for retention of the teeth. If the teethrelapse, a dental practitioner can reattach the primary magnets asneeded and, if necessary, cut windows through the retainer, so that thepatient may wear the secondary magnet holder on top of the retainer tohelp move the teeth back to their proper positions.

In a third method of use, a dental practitioner will attach the primarymagnets to the teeth. An impression will then be taken such as, bynon-limiting example, a polyvinyl siloxane (PVS) impression. Athree-dimensional (3-D) scan of the impression will be taken and datarelated thereto will be uploaded to a server. A computer softwareprogram in communication with the server will analyze the 3-D data andoutput one or more of the following: (1) data used to form the first, ormultiple, or all of the aligner trays (including in some implementationsthe final retainer) that will be used during orthodontic treatment ofthe teeth; (2) data used to determine one or more of size, strength,location, and number of primary magnets on the teeth of the patient; (3)data used to determine which of a number of secondary magnet holders andsecondary magnets to use; (4) an estimation of tooth movement duringorthodontic treatment, and; (5) a calculation of the force and/or timeneeded to perform each incremental, or the full, tooth movement for eachtooth to be moved. In implementations this process may be repeated eachtime the new aligner tray is to be replaced, and in such implementationsthe computer software program may utilize the some or all prior 3-D datain conjunction with the new 3-D data collected during the treatmentprocess to perform its functions.

In various implementations, the computer software program may calculateattractive forces between magnets (or between magnets and magnetizableelements). In implementations the computer software program maycalculate repelling forces between magnets. In implementations thecomputer software program may utilize the following equation indetermining the force between two magnets by estimating the forcebetween two magnetized surfaces, where A is the area of each surfacemeasured in square meters, H is their magnetizing field measured inAmps/meter, μ₀ is the permeability constant which equals 4π10⁻⁷ Tm/A(Tesla meters per amp) and B is the magnetic flux density measured inTeslas.

$F = {\frac{\mu_{0}H^{2}A}{2} = \frac{B^{2}A}{2\mu_{0}}}$

As this equation is more valid for cases in which the effect of fringingis negligible and the volume of the gap between magnets is much smallerthan the dimensions of the magnetized material, in implementations inwhich fringing is not negligible and/or the gap is not much smaller thanthe dimensions of the magnetized material, other equations to correctfor such effects may be utilized by the computer software program.

The practitioner of ordinary skill in the art will readily understandthat the computer software program may utilize a multitude of equations,values, inputs, logic, and the like to calculate forces that will beexerted on teeth, which in some cases may be estimated by calculatingthe force between two isolated magnets, such as one primary magnet andone secondary magnet, or which in other cases may be estimated bycalculating the cumulative force on each primary magnet taking intoaccount all other primary and secondary magnets of the magnetic toothalignment device that exert a non-negligible force thereon.

In various implementations, a magnetic tooth alignment device may alsocause movement of the teeth through other than magnetic forces. Forinstance, the aligner tray may also place mechanical pressure on one ormore teeth to move them, by contacting the teeth directly, in additionto/in combination with the magnetic forces that are exerted on the teethdue to the magnets. In various implementations, the magnetic toothalignment device could be used in conjunction with other types of toothmovement devices (braces, etc.) to move the teeth to their desiredlocations.

In particular implementations, the magnetic tooth alignment device whenused for extrusion may provide any of the following: light, constantforces such as, by non-limiting example, 15 g (or about 15 g) foranterior teeth and 50 g (or about 50 g) for posterior teeth; a steady,slow rate for tooth movement such as, by non-limiting example, no morethan about 2.0 mm per month, and/or; a retention and stabilizationperiod of no less than one month for every month of active extrusion.

In some implementations the magnetic tooth alignment device may be usedfor crowns that have broken off and need crown lengthening. In generalsuch crowns do not have enough tooth structure for brackets, so the onlyoption for treatment has been a crown lengthening procedure. Thisprocedure requires cutting gum away from bone and then grinding boneaway from tooth until adequate tooth structure is present to cement acrown. As an alternative to this procedure, the magnetic tooth alignmentdevice may be utilized, with a primary magnet placed on the remainingtooth structure and the secondary magnet used to extrude the tooth to anideal length without a need for surgical crown lengthening.

In various implementations, the secondary magnet holder may be formed byincorporating a magnet into or on an athletic mouth guard or mayotherwise have the same shape, or a shape similar to an athletic mouthguard, such as are used in contact sports like football, boxing, etc.

In implementations of primary and secondary magnets that includeneodymium the amount of neodymium may vary based on the shape of themagnet. Some implementations of primary and secondary magnets willconsist 100% of an alloy of neodymium, iron and boron in the Nd₂Fe₁₄Btetragonal crystalline structure. The primary magnets 6 in variousimplementations will have a size of, or of about, 1 mm×2 mm with athickness of, or of about, 0.5 mm to 0.75 mm. The primary magnets mayhave a size of, or of about, 1 mm×2 mm×0.75 mm, and may have a taperedshape. The primary magnets may have a size of, or of about, 1 mm inheight, 2 mm in width, and 0.75 mm thick. The thickness of the primarymagnet may be, or may be about, 0.5 mm at the gingival aspect of thetooth and increase to, or to about, 0.75 mm thickness at the incisaledge of the tooth. A polyurethane coating may be placed over the primaryand secondary magnets to make them biocompatible. The polyurethanecoating may be, or may be about, 0.001 mm thick, coating the entiremagnet. A second coating may be placed over the polyurethane coating,which may be a composite/resin of, or of about, 0.2 mm thick, on thebuccal surface, to create the tooth colored coating, and may have theappearance of an enamel coating. Carbon fiber coatings may be used insome implementations on the primary and/or secondary magnets to providethe tooth colored coating, which may be thinner than 0.2 mm thick.

In various implementations, the secondary magnet holder 14 may be formedof the aforementioned ESSIX material. The secondary magnet holder may beformed of any of many different polymeric materials commonly used toform athletic mouth guards or mouthpieces which may be softer and allowfor a more cushioned bite compared with the ESSIX material. Variousother polymer materials may be used to form the secondary magnet holder.In implementations the secondary magnet holder may have an arched shapeand be a one-size-fits-all form. The segmented nature of the secondarymagnet holder shown in FIGS. 1-5 may facilitate the ability of thesecondary magnet holder to have this one-size-fits-all functionality. Insome cases the secondary magnet(s) will be held in place within, orattached to, the secondary magnet holder at least partly from pressureon or from the segments. This pressure may comprise a transverse forceor a minor squeeze which may be not enough to cause discomfort or toothmovement. Magnetic molar attachments may be placed on the buccal surfaceof upper molars, which in some cases may be rectangular and may havedimensions of, or of about, 1 mm×2 mm. The rectangular magnetic molarattachments may aid in holding the secondary magnet holder in the mouth,the secondary magnet and/or other magnet(s) of the secondary magnetholder being attracted thereto. The aligner tray and the magnetic molarattachments may form a convexity (convex shape) to which the secondarymagnetic holder couples.

The magnetic tooth alignment device may have the following attributes:greater rate of tooth movement than is possible with conventional clearaligners alone; more full tooth movement (closer to desiredend-positioning) than is possible with conventional clear alignersalone; less overstressing of teeth than occurs with wire movement ofteeth (using braces)—this may reduce root resorption and unneeded toothmovement (tipping); increased ability for extrusion movement of teethover conventional clear aligners; greater success rate for toothextrusion (compared to about 29% success rate for conventional clearaligners); more predictable movement of teeth during treatment thanconventional clear aligners and braces; more types of movement of teeththan are possible with conventional aligners alone; no need to useoverlay wires to avoid tipping of teeth adjacent to teeth that areintentionally being moved; increased ability for tooth expansioncompared to conventional aligners, which are generally incapable ofproviding the forces needed for proper expansion, and more predictableexpansion, without having to change the clear aligner material (i.e.,while using the same material for the aligner tray as is used forconventional clear aligners); allowing placement of magnets on thelingual surfaces of dentition, thus providing a non-visible alternativeto braces; less bulky attachments in general as compared with braces andconventional tooth-movement technology, and; the ability for expose andbond procedures—conventional clear aligner treatment does not involveexpose and bond procedures, thus requiring a patient to turn to surgeryor braces as the only options for such treatment—with the ability toplace a primary magnet on an exposed tooth the secondary magnet may putthe necessary pull on the tooth to extrude it out of bone and gum.

In implementations the primary magnets 6 and/or secondary magnets 22 maybe formed of a magnetic resin and/or a composite material havingmagnetic filings or a magnetic powder mixed with a cement or glue—suchas by non-limiting example a clear tetracyanoethylene magnetic powder.The primary magnets and secondary magnets may have coatings to increasetheir biocompatibility and/or to prevent corrosion or other effects onthe magnet. The primary magnets and/or secondary magnets may be formedof a magnetic material added to a cement, resin or adhesive which isthen formed into the desired shape.

The primary and secondary magnets may, in implementations, be fabricatedby Dexter Magnetics of Elk Grove Village, Ill. Coatings placed on theprimary and/or secondary magnets may, in implementations, be provided orapplied by Paratronix, Inc. of Attleboro, Mass.

Various details disclosed herein with regards to primary magnets, suchas size, shape, manufacturing techniques, color, coatings, placement ona tooth, etc., may also apply to magnetizable elements 5 that are notactually magnets.

Although the magnetizable element 5 in FIGS. 1-5 is represented as amagnet, it is to be understood that the magnetizable element in any ofthese implementations may be a non-magnet instead, such as a metal thatis attracted to the secondary magnet 22 by virtue of its being amagnetizable metal (stainless steel, by non-limiting example).

Referring now to FIG. 6, in implementations a magnetic tooth alignmentdevice (device) 24 includes a magnetizable element 25 attached to atooth 2. The magnetizable element 25 in implementations may be formed ofa magnet, such as primary magnet 26, though in other implementations itmay be a non-magnetic element, such as a metal. The device 24 shown inFIG. 6 shows a tooth 2 with a magnetizable element (in this case firstprimary magnet 28) on the front (buccal) side of the tooth and thedevice 24 shown in FIG. 7 shows a tooth with a magnetizable element (inthis case second primary magnet 30) on the back (lingual) side of thetooth. The shapes of first primary magnet 28 and second primary magnet30 are shown in greater detail in FIGS. 15-20. FIGS. 15-17 show top,side, and perspective views, respectively, of first primary magnet 28.FIGS. 18-20 show top, side, and perspective views, respectively, ofsecond primary magnet 30. A third primary magnet 32, having acylindrical shape, is shown in FIGS. 21-23. FIGS. 21-23 show top, side,and perspective views, respectively, of third primary magnet 32.

Although the first primary magnet 28 is shown on the front (buccal) sideof the tooth and the second primary magnet 30 is shown on the back(lingual) side, in other implementations all of the magnetizableelements could have the shape of one or the other examples given inFIGS. 15-23, or any other shape. For example all magnetizable elements,whether on the front, back, side, or bottom of the tooth, could have theshape of the first primary magnet, or the second primary magnet, or thethird primary magnet. Likewise, magnetizable elements having the shapeof the first primary magnet could be located on the lingual side of thetooth (or on the sides), and magnetizable elements having the shape ofthe second primary magnet could be located on the buccal side of thetooth, or on the sides, etc. The user (dentist or other professionalapplying the magnetizable elements) may choose which shapes/sizes to usein each scenario, or a computer program as previously described may makesuch a determination. As shown in FIGS. 18-20, the shape of the secondprimary magnet 30 is the shape of a cylinder with one of its basestitled at an angle. Other shapes could be used than those describedherein for any of the magnetizable elements and, indeed, custom shapesand molded shapes could be used to conform to a tooth so as to moreeasily blend in to the appearance of the tooth.

In implementations in which the magnetizable elements 25 are notmagnets, they may be formed of stainless steel. In implementations inwhich a powder is used mixed in a binder one or more magnetic powders orsalts may be used, such as salts of various first row transition metals,cyano salts, and the like. In implementations in which the magnetizableelements 25 are formed of steel they may be 17-4 stainless steel whichmay be purchased in a rod and machined to the proper shape and size. Astainless steel magnetizable element may have the same shape as thefirst primary magnet 28, which includes a half-sphere having a radiusof, or of about, 1 mm. When viewed from the side as seen in FIG. 16 thehalf-sphere portion thus has a height of 1 mm and a diameter of 2 mm.The shape shown in FIGS. 15-16 includes the shape of a half-sphere atopthe shape of a cylinder, but in other implementations a magnetizableelement could have simply the shape of a half-sphere without thecylindrical portion.

When a cylindrical shape is used, as in FIGS. 21-23, the shapes may havea thickness (height in FIG. 22) of 1-2 mm, or about 1-2 mm, with adiameter of, or of about, 2 mm. When the magnetizable elements areformed of a non-magnetic material, such as steel, the magnetizableelements will not attract or repel one another. This may in some casesbe advantageous because, in the event that a plurality of magnetizableelements are swallowed, there will be no magnetic attraction orrepulsion of the magnetizable elements in the digestive tract of thepatient. Additionally, removing magnetic interactions betweenmagnetizable elements on neighboring teeth may reduce unwanted forcesbetween teeth and may make modelling the movement of the teeth, withsoftware as described above, simpler.

Various white or tooth-colored coatings may be applied to themagnetizable elements to make them blend in better. In implementationsthe white or tooth-colored coatings may be coatings sold and/ordistributed and/or applied by Liquipel LLC of Santa Ana, Calif. Anotherhypoallergenic coating may be applied under or over this coloredcoating, and may be sold and/or distributed and/or applied under thetrade name PARALYENE by Jaro Corp. of Ipswich, Mass. or Paratronix Inc.of Attleboro, Mass. PARALYENE coated magnets have been used in humanstudies. The coatings may be, or may be about, 0.001 mm thick, and maycoat the entire surface of the magnetizable element.

FIGS. 6 and 7 both show an aligner tray 34 that is custom shaped with aprotrusion 36 that forms or defines a cavity 37 between the aligner trayand the magnetizable element. The secondary magnet holder 38 shown inFIGS. 6-7 has substantially the same shape as the aligner tray and clipsover the aligner tray to stay on place using only a friction fit or, insome implementations, a friction fit assisted by the magnetic attractionof the secondary magnet(s) 40 towards the magnetizable element(s) 25. Incases wherein the magnetizable element 25 is attracted towards thesecondary magnet 40, the magnetizable element 25 is allowed somemovement within the cavity until it abuts the inner wall of the alignertray 34, at which point the movement stops and a new aligner tray and/orsecondary magnet holder may be utilized to allow and/or effect furthermovement. As described above with respect to device 4, the use of device24 may include the use of a series of aligner trays and/or secondarymagnet holders, a series of positions and placements of magnetizableelements, and various of these may be computer simulated or generatedusing software that models the movement of the teeth based on magneticand other forces over time.

A first shape 42 for a secondary magnet 40 is shown in FIGS. 24-26, anda second shape 44 for a secondary magnet is shown in FIGS. 27-28. FIGS.24-26 show top, side, and perspective views, respectively, of firstshape 42. This is an arcuate shape or a dental arch shape 42. As can beseen in FIGS. 25-26 the height is greater than the thickness in someimplementations and the arc spans close to a 90 degree arc. Otherversions may have other dimensions. In various implementations, an archshaped secondary magnet may have dimensions of, or of about, 1⅛ inchouter radius, 1 inch inner radius, ⅛ inch height, ⅛ inch thickness, anda 45 degree arc. FIGS. 27-29 show top, side, and perspective views,respectively, of a second shape 44 for a secondary magnet, which has theshape of a right rectangular cuboid. Other shapes may be used for thesecondary magnets, and indeed any custom shape could be used as desiredby a user or as generated by a computer software program for propertooth movement.

The secondary magnet(s) 40 may in implementations be formed of neodymium(NbFeB), though other magnetic materials may be used. The secondarymagnets 40 may be encased in the secondary magnet holder, and inimplementations the secondary magnetic holder may be a clear plastictray similar to, and even in some cases formed of the same material as,aligner tray 34. The secondary magnets 40 could be covered with a whiteor tooth-colored coating and/or hypoallergenic coatings as well, similarto the magnetizable elements 25, as described above.

FIG. 8 shows an exploded view of a device 24 for use with an upper rowof teeth 2. The aligner tray 34 has a plurality of protrusions 36 thatare positioned to line up with magnetizable elements 25 so that a cavity37 is formed between the aligner tray and the magnetizable elements whenthe aligner tray is encased over the plurality of teeth. Although FIG. 8numbers the magnetizable elements as first primary magnets 28, it is tobe understood, as described herein, that the magnetizable elements insome implementations are not magnets, but are stainless steel or formedof some other metal or magnetizable element that is not independentlymagnetic. The secondary magnet holder 38 is shown, which generally has ashape substantially similar to that of the aligner tray (thoughdifferent in some regards, as it is larger, to be able to fit over thealigner tray 34, and as it may not have protrusions as the aligner traydoes). The secondary magnet holder 38 is seen with a number of secondarymagnets 40 encased therein. In use the aligner tray 34 is “clipped” intoplace or otherwise slid over the row of teeth so that it is held inplace using a friction fit, and the secondary magnet holder 38 is thenalso clipped or slid in place over the aligner tray 34 so that it alsois held in place using a friction fit. The device 24 of FIG. 9 hassimilar elements and is used in a similar fashion, but is designed for abottom row of teeth. The arrows in FIGS. 8-9 represent the movement ofthe elements together to assemble device 24 on either the top row ofteeth or bottom row of teeth, respectively.

FIGS. 10-14 representatively illustrate different types of toothmovement that may be effectuated using a device 4 or 24. In FIG. 10tooth extrusion is representatively illustrated. The magnetizableelement 25 in this case may be either a magnet or a non-magnet, such assteel or another metal, and is attracted towards the secondary magnet40, thus pulling the tooth downwards. In FIG. 11 tooth intrusion isrepresentatively illustrated. The magnetizable element 25 in this casemust be a magnet, and the poles of magnetizable element 25 and secondarymagnet 40 are aligned so that the two repel one another, thus pushingthe tooth upwards. In FIG. 12 tooth rotation is representativelyillustrated. The magnetizable element 25 in this case could be either anon-magnet or a magnet. It is attracted towards the secondary magnet 40and is thus used to twist or rotate the tooth to a proper position. Asmay be envisioned, in this case a secondary magnet could be used as thelingual side as well, and magnetizable element 25 could be a magnet,with the elements oriented so that the lingual side secondary magnetrepels the magnetizable element and the buccal side secondary magnetattracts it, thus achieving increased rotation. This same concept may beapplied to other tooth movements herein wherein one side or portion of atooth is repelled in this way and another side or portion is attracted,to increase or maximize force and movement of a tooth.

FIG. 13 representatively illustrates bodily movement of a tooth(proclining, reclining, or “tipping”). In this case the aligner tray issized/shaped to allow a tipping movement of the tooth and the dashedoutline represents the desired end-position (or intermediate position)of the tooth. The magnetizable element 25 in this case may be either amagnet or a non-magnet, and it is attracted towards the secondary magnet40. The same movement may be effectuated through repulsion at thelingual side, in which case the magnetizable element would need to be amagnet. FIG. 14 shows a representative example of tooth or jaw expansionachieved using device 4 or 24. The aligner tray and secondary magnetholder are not shown, so that the primary magnets 26 and secondarymagnets 40 may be more clearly seen. In this case actual magnets(primary magnets 26) are used so that they can be repelled by secondarymagnets 40 by proper alignment of the magnetic poles of each. In each ofFIGS. 10-14 the arrows illustrate the projected movement of the tooth orteeth.

When device 24 is used, the aligner tray 34 is configured so that it atleast partially encases a plurality of teeth of the patient as well asthe magnetizable elements, and the secondary magnet holder 38 isconfigured so that it at least partially encases the aligner tray 34. Inthe drawings aligner tray 34 fully encases a plurality of teeth and thesecondary magnet holder 38 fully encases the aligner tray 34. Both thealigner tray 34 and the secondary magnet holder 38 may be formed oftransparent polymers, and the aligner tray 34, as shown in the drawings,in implementations includes no magnets. The aligner tray 34 may be heldto the teeth using only a friction fit and the secondary magnet holder38 may be held to the aligner tray using only a friction fit, asdescribed. Correspondingly, each may be easily removed and replaced by auser as necessary or as desired.

The magnetizable element may be formed using a powdered metal ormagnetic material mixed with an adhesive or it may be a cement magneticmaterial or cement metallic material. The magnetizable element, when itis a solid element such as a solid metal or magnet element, may beadhered to the tooth using an adhesive which may later be removed usinga solvent to remove the magnetizable element.

In places where the description above refers to particularimplementations of magnetic tooth alignment devices and related methodsand implementing components, sub-components, methods and sub-methods, itshould be readily apparent that a number of modifications may be madewithout departing from the spirit thereof and that theseimplementations, implementing components, sub-components, methods andsub-methods may be applied to other magnetic tooth alignment devices andrelated methods.

What is claimed is:
 1. A magnetic tooth alignment device, comprising: afirst magnetizable element configured to be adhered to a tooth of apatient; an aligner tray configured to at least partially encase aplurality of teeth of the patient and the first magnetizable element,and; a secondary magnet holder configured to at least partially encasethe aligner tray, the secondary magnet holder comprising a secondarymagnet configured to magnetically interact with the first magnetizableelement when the secondary magnet holder is partially encasing thealigner tray; wherein the secondary magnet holder is reversiblycouplable to the aligner tray.
 2. The device of claim 1, wherein thealigner tray is formed of a polymer.
 3. The device of claim 1, whereinthe aligner tray is transparent.
 4. The device of claim 1, wherein thealigner tray includes no magnets.
 5. The device of claim 1, wherein thealigner tray is configured to couple with the plurality of teeth of thepatient using only a friction fit.
 6. The device of claim 1, wherein thealigner tray is configured to fully encase the plurality of teeth of thepatient and to fully encase the first magnetizable element.
 7. Thedevice of claim 1, wherein the aligner tray comprises a protrusiondefining a cavity between the aligner tray and the first magnetizableelement.
 8. The device of claim 1, wherein the secondary magnet holderis shaped substantially similarly to the aligner tray.
 9. The device ofclaim 1, wherein the secondary magnet holder is configured to couplewith the aligner tray using only a friction fit.
 10. The device of claim1, wherein the first magnetizable element is formed of one of a powderedmagnetic material mixed with an adhesive and a cement magnetic material.11. The device of claim 1, wherein an inner wall of the aligner tray isconfigured to stop movement of the tooth when the first magnetizableelement contacts the inner wall of the aligner tray.
 12. A magnetictooth alignment device, comprising: a first magnetizable elementconfigured to be adhered to a tooth of a patient; an aligner trayconfigured to at least partially encase a plurality of teeth of thepatient, the aligner tray comprising a protrusion defining a cavitybetween the aligner tray and the first magnetizable element, the alignertray comprising no magnets; and; a secondary magnet holder configured toat least partially encase the aligner tray, the secondary magnet holdercomprising a secondary magnet configured to magnetically interact withthe first magnetizable element when the secondary magnet holder ispartially encasing the aligner tray; wherein the secondary magneticholder is reversibly couplable to the aligner tray.
 13. The device ofclaim 12, wherein the secondary magnet holder is configured to couplewith the aligner tray using only a friction fit.
 14. The device of claim12, wherein the aligner tray is formed of a polymer.
 15. The device ofclaim 12, wherein the aligner tray is transparent.
 16. The device ofclaim 12, wherein the secondary magnet holder comprises a shapesubstantially similar to the aligner tray.
 17. The device of claim 12,wherein the secondary magnet comprises a dental arch shape.
 18. Amagnetic tooth alignment device, comprising: a first magnet configuredto be adhered to a tooth of a patient; an aligner tray configured to atleast partially encase a plurality of teeth of the patient and the firstmagnet, and; a secondary magnet holder configured to at least partiallyencase the aligner tray, the secondary magnet holder comprising asecondary magnet configured to magnetically interact with the firstmagnet when the secondary magnet holder is partially encasing thealigner tray; wherein the secondary magnetic holder is reversiblycouplable to the aligner tray.
 19. The device of claim 18, wherein thealigner tray includes no magnets.
 20. The device of claim 18, whereinthe secondary magnet holder comprises a shape substantially similar tothe aligner tray.